Gülnur Tarhan

Distribution of Spoligotyping Defined Genotypic Lineages among Drug-Resistant Mycobacterium tuberculosis Complex Clinical Isolates in Ankara, Turkey

Background Investigation of genetic heterogeneity and spoligotype-defined lineages of drug-resistant Mycobacterium tuberculosis clinical isolates collected during a three-year period in two university hospitals and National Tuberculosis Reference and Research Laboratory in Ankara, Turkey. Methods and Findings A total of 95 drug-resistant M. tuberculosis isolates collected from three different centers were included in this study. Susceptibility testing of the isolates to four major antituberculous drugs was performed using proportion method on Löwenstein–Jensen medium and BACTEC 460-TB system. All clinical isolates were typed by using spoligotyping and IS6110-restriction fragment length polymorphism (RFLP) methods. Seventy-three of the 95 (76.8%) drug resistant M. tuberculosis isolates were isoniazid-resistant, 45 (47.4%) were rifampicin-resistant, 32 (33.7%) were streptomycin-resistant and 31 (32.6%) were ethambutol-resistant. The proportion of multidrug-resistant isolates (MDR) was 42.1%. By using spoligotyping, 35 distinct patterns were observed; 75 clinical isolates were grouped in 15 clusters (clustering rate of 79%) and 20 isolates displayed unique patterns. Five of these 20 unique patterns corresponded to orphan patterns in the SITVIT2 database, while 4 shared types containing 8 isolates were newly created. The most prevalent M. tuberculosis lineages were: Haarlem (23/95, 24.2%), ill-defined T superfamily (22/95, 23.2%), the Turkey family (19/95, 20%; previously designated as LAM7-TUR), Beijing (6/95, 6.3%), and Latin-America & Mediterranean (LAM, 5/95 or 5.3%), followed by Manu (3/95, 3.2%) and S (1/95, 1%) lineages. Four of the six Beijing family isolates (66.7%) were MDR. A combination of IS6110-RFLP and spoligotyping reduced the clustering rate from 79% to 11.5% among the drug resistant isolates. Conclusions The results obtained showed that ill-defined T, Haarlem, the Turkey family (previously designated as LAM7-TUR family with high phylogeographical specifity for Turkey), Beijing and LAM were predominant lineages observed in almost 80% of the drug-Resistant M. tuberculosis complex clinical isolates in Ankara, Turkey.

Clinical importance of serum neopterin level in patients with pulmonary tuberculosis

OBJECTIVE Neopterin is a sensitive marker for cell-mediated immune response. Because of this, the neopterin levels of body fluids show cell-mediated immune response in different infectious diseases which involve T cells and macrophages. The aim of this study was to determine the clinical importance of neopterin levels in patients with tuberculosis and compare with those levels of healthy subjects. METHODS Seventy patients with tuberculosis (46 newly diagnosed cases, 15 relapse cases, and 9 multidrug-resistant tuberculosis cases) and 18 healthy adult individuals were included in the study. Neopterin concentrations were measured by the ELISA method according to the protocol of the manufacturer. Chi-square test was used in statistical analysis; p⩽0.05 was considered statistically significant. RESULTS Serum mean neopterin levels were 23.74±21.8nmol/L (median: 18.3) in newly diagnosed patients with pulmonary tuberculosis; 28.69±21.2nmol/L (median: 21.2) in relapse patients and 31.28±14nmol/L (median: 25.4) in multidrug-resistant tuberculosis cases, respectively. Serum mean neopterin levels were 4.03±5.12nmol/L (median: 5.1) in healthy subjects. The serum neopterin levels were found to be significantly higher in patients with tuberculosis than the control group. There was a statistically significant correlation between neopterin positivity (neopterin level ⩾10nmol/L was accepted to be positive) and clinical symptoms of hemoptysis and weight loss. Besides statistically significant correlations between neopterin positivity and hemoglobin level, sedimentation rate, mean leukocyte count and radiological involvement (localized or diffuse) were determined. CONCLUSION Serum neopterin levels can be used as a helper laboratory finding for the diagnosis of patients with tuberculosis. For this aim, further controlled studies are needed.

The Effect of Three Decontamination Methods on COBAS AmplicorMycobacterium tuberculosis PCR Assay

In this study, we evaluated the effect of three decontamination-homogenization-concentration (DHC) methods on COBAS Amplicor Mycobacterium tuberculosis (MTB) PCR system (Roche Diagnostics, Inc., Branchburg, USA) in three different periods. A total of 1210 clinical specimens (602 pulmonary, 608 extrapulmonary specimens) were investigated. Specimens were decontaminated periodically using three DHC methods (Method A: 3% NaOHtrisodium citrate-N-acetyl-L-cysteine (NALC), Method B: 4% NaOH-Bromothymol Blue (BTB) method-Direct, Method C: 4% NaOH-BTB method-irrigation before DNA extraction method). Definitive results were obtained from 1011 (83.6%) of 1210 samples. The inhibition rates according to DHC methods (Method A, B, C) were respectively 3.3% (10/302), 4.3% (7/162) and 17.3% (24/138) for pulmonary samples; 10.3% (30/291), 19.5% (33/169) and 35.1% (52/148) for extrapulmonary samples; 6.7% (40/593), 12.1% (40/331) and 26.5% (76/286) for all samples respectively When inhibition rates were compared in terms of samples types and numbers, high inhibitor rates were found in urine 24.4%, cerebrospinal fluid (CSF) 9.5% and gastric lavage fluid (GLF) 7.6%, respectively. Using culture results as standard, the sensitivity, specificity, positive (PPV) and negative (NPV) predictive values of COBAS Amplicor MTB PCR assay were, respectively, 68.2%, 99.1%, 75% and 98.8% for the method A, 66.7%, 98%, 75% and 96.9% for method B, 75.0%, 98.9%, 75% and 98.8% for method C. We conclude that laboratories planning to use nucleic acid amplification (NAA) methods as supplement to conventional methods, should be prefer 3% NaOH-trisodium citrate-NALC method.

Extensively Drug-resistant Tuberculosis Strains in National Tuberculosis Reference Laboratory Between 2005 And 2010, Turkey

Frequency, rate and trend of extensively drug-resistant [XDR] tuberculosis [TB] in Turkey are not clear and not known very well. In this study, it was aimed to try to determine and to confirm the frequency of XDR-TB strains among Multi-Drug Resistant [MDR] TB cases. A total of 4119 M. tuberculosis strains were analyzed. The strains were collected from 19 TB centers [hospitals or regional TB laboratories] including National TB Reference Laboratory [NTRL]. Two hundred ninety-seven 297 [7.2%] M. tuberculosis strains were detected as MDR-TB. Among all MDRTB cases, 37 [12.5%] were pre-XDR-TB, and 8 [2.7%] were XDR-TB.